The present invention relates to an air handling system (i.e. for pressure equalization, attenuation, redistribution or the like) which has a forced air treatment unit or component and, for example, a forced air ventilator unit or component. These air handling units are coupled to a common duct system. These air handling units may take any (known) form. These air handling units are associated with air blower means which are commonly provided with electric motors which may be selectively or independently activated by (known types of) control mechanisms for controlling the various motors for the various operation modes of the air handling system. In the following, particular attention will be given, by way of example, to systems with air ventilators.
Buildings such as houses, apartment buildings, etc., are quite often constructed or renovated so as to be air tight in addition to being insulated so as to facilitate heating, humidifying and/or cooling of the indoor environment provided therein. While such air tight insulation construction provides heating/cooling cost benefits, such construction can also unfortunately prevent or inhibit fresh air from entering a building. The lack of fresh air may lead to the accumulation of unwanted elements in the indoor air, such as particles of dust, cooking vapours and odours as well as other types of indoor air pollutants.
As a result, buildings are either being renovated or initially constructed so as to be outfitted with one or more air ventilator units which can introduce outside fresh air into the indoor space(s) of buildings, provide purification of the air, exhaust indoor air to the outside environment or a combination thereof, etc. Examples of known types of ventilation devices are illustrated in U.S. Pat. Nos. 5,193,630, 5,771,707, 6,209,622, 6,257,317, 6,289,974 as well as in U.S. patent application Ser. No. 10/158,492 published under no. 20030013407; the entire contents of each of these patent documents is incorporated herein by reference.
An air duct system of an existing building may already be connected to an air treatment unit which either heats, humidifies and/or cools air for delivery to the indoor space(s) of the building; examples of such air treatment units include forced air furnaces, air conditioners (i.e. coolers), humidifiers, etc. Air treatment may thus comprise an air heating stage, an air cooling stage, etc. For an existing building, indoor air may be delivered to the air treatment unit by the air supply or input portion of the air duct system and the heated or cooled air may then be circulated throughout the building through the return or output portion of the air duct system. Thus, in the case of an existing building, a relatively efficient way to integrate an air ventilator unit with the building is to exploit the existing air duct system (i.e. exploit existing building air duct(s)) so as to form an integrated air handling system. A building may of course be initially constructed with an air ventilator unit being connected to such a common duct work system.
An integrated air handling system may be configured so as to have a ventilation mode (i.e. ventilation only), an air treatment mode (e.g. heating only) and a combination mode (e.g. simultaneous heating and ventilation). During ventilation mode operation only, the ventilator blower means may be activated (e.g. an electric motor thereof is electrically energized); during air treatment mode only, the air treatment air blower means may be activated (e.g. an electric motor of a furnace air blower means is electrically energized); and during combination mode both the ventilator blower means and the air treatment air blower means may be simultaneously activated (e.g. an electric motor thereof is electrically energized). An electric motor may be electrically energized by being electrically connected to a source of electrical power or energy via appropriate electrical wiring and electric switching assembly (i.e. in any known manner).
There are, however, some problems which may arise from hooking up an air ventilator unit to an air duct system connected to an air treatment unit such as a furnace unit. For example, it has been proposed to couple the stale air inlet and fresh air outlet of the air ventilator unit on the same (e.g. upstream) side of the duct system feeding air to the air treatment unit. However, if the stale air inlet and fresh air outlet of the air ventilator unit, are coupled to the air duct system too closely together, then during ventilation mode operation when the air treatment unit is off (e.g. the furnace blower mean is not energized), a short circuiting of the air flows entering and exiting the air ventilator unit may occur. This is not desirable because it leads to a portion of the air being treated over and over again by the air ventilator unit.
The simplest proposed solution to this problem is to provide a blocking system between the air inlet and the outlet of the air ventilator unit. In this way the short circuiting is prevented. This solution can, however, cause additional problems related to impaired flow of air to the air treatment unit. The reason for this is that air treatment units (e.g. forced air furnace units) usually drive air through the air circulation system at much higher volumes than that which pass through an air ventilator unit. If the passage to the air treatment unit were to be blocked between the air inlet and outlet of the air ventilator unit, then, when running both the air treatment unit and the air ventilator unit simultaneously, all the air would have to pass through the air ventilator unit and the air treatment unit might then be unable to operate at its full capacity and lead to equipment break down; a reduced air flow through an air treatment unit such as a furnace for example may not only lead to equipment breakdown but may also result in overheating of the furnace which at worst, may cause fire ignition
In order to inhibit such short circuiting it is possible to place the air ventilator unit in parallel with an air treatment unit such as a furnace unit, namely to couple the stale air inlet and fresh air outlet of the air ventilator unit to the air duct system respectively upstream of the furnace and downstream of the furnace, e.g on opposite sides of the furnace unit. This coupling system may however, also lead to a reduced air flow problem, when both the furnace unit and air ventilator unit are operating at the same time. In this configuration the air ventilator unit will siphon off some of the air normally destined to pass through the furnace unit; this reduced air flow through the furnace may also result in overheating of the furnace with the attendant fire danger.
As can be seen from the above, there is an ongoing need for a system for delivering fresh air to an indoor environment.
It would be advantageous to have an air handling system having an air treatment unit or component as well as an air ventilator unit or component which are connected or coupled to a common duct system so as to inhibit short circuiting of air flow through the air ventilator unit during a ventilation mode operation thereof.
It would also be advantageous to have an air handling system having an air treatment unit or component as well as an air ventilator unit or component which are connected or coupled to a common duct system so as to be able to attenuate or modulate reduced air flow to the air treatment unit during combination mode operation of such an integrated air handling system.
It would be advantageous to have an air handling system able to adjust air flow in reaction to the air pressure in the secondary duct system associated with a second air handling unit or component so as to be able to equilibrate the resulting airflow entering the air treatment component and inhibit or avoid excessive choking off of the original equipment in place.
It in particular would be advantageous to have an air handling system able to adjust air flow in reaction to the air pressure in the secondary duct system associated with the ventilation unit or component so as to be able to equilibrate the resulting airflow entering the air treatment component so as to inhibit or avoid excessive choking of the air treatment component, i.e. choking off of the original equipment (e.g. furnace) in place.